There are many types of window coverings available on the market, such as blinds, pleated shade, roman shade and the like. They mainly are installed on windows or doors in houses to block sunshine and provide decorative function. While consumer's requirements may be different, safety always is an important issue. Taking this issue into account, an electrically driven window covering usually is adopted to control rising up or lowering down of the window covering. However, the electric window covering still has problems when in use, notably:
1. When the conventional electric window covering is in a no power condition the motor and gear box are not functioning, lowering down or rising up the window covering by hands is difficult.
2. When the conventional electric window covering is in a no power condition to lower down or roll up the window covering at a desired elevation and anchored there is more difficult. As a result the practicality of the window covering suffers.